Can I program X button to completely close program?

[Rockadile]

I would like to have the program fully close (like ⌘+Q) instead of being idle in the background when I click the red X button on a window. Is that possible?

 

[Dave Braine]

In general, only Applications that can have only one window; eg, iPhoto and iMovie can be quit by the red button.

What's wrong with Cmd+Q. Easily done with the finger and thumb of one hand.